1. Field of Invention
The present invention relates to a package for electronic elements and packaging method more particularly to a stacked package for electronic elements and packaging method thereof.
2. Related Art
A process of packaging electronic elements, also called electronic packaging, provides protection for the electronic element and further electrical connection between the electronic element and other external elements. The packaging process generally is a backend process in the semiconductor manufacturing, and therefore is not considered as important as the front-end process. However, the packaging process determines the size and the cost of the final product, which may also be of importance in the commercial success of the final product.
Conventionally, electronic packages are classified as a single chip package (SCP) type or a multi chip package (MCP) type, according to the amount of integrated chips (IC) mounted in the electronic package. The multi chip package further includes a multi chip module (MCM). MCP type package has become the main stream in the current field of electronic packaging because of several advantages such as a small size, low production costs, a high-density wiring and high performance. Further reducing the manufacturing cost and the size of the package has always been the goal of the research and development made by current package manufacturers.
Usually, Flip-Chip (According to your following description, I think use flip-chip is better than bga) is used as external connection to achieve the electrical connection between the chips in the multi chip package. Such a type of electronic package needs a lot of processing steps such as mask forming, a photolithography process, sputtering, plating, and solder ball forming, which renders the whole process complex and increases the possibility of destabilizing it. The packaging costs are thereby increased. Furthermore, the vias of the chip serve as vertical conductive paths of the chip. A conductive material has to be filled respectively in the vias. The alignment of the conductive material and filling of the conductive material in the vias constitute a difficult operation, which possibly destabilizes the yield and not is workable in mass production.